Active Vibration Control of Rotor: Test Environment with Non-Contact Magnetic Actuator

The goal of this work was to set up a test environment for active vibration control of rotors, to study the dynamics of the system, and to design a control system to control the rotor vibrations. The principal idea was to control vibrations with a non-contacting magnetic actuator without a load-carrying function. The rotor was supported by conventional bearings at its ends. The test environment consisted of a rotor test rig, a magnetic actuator, and a programmable control unit. The test environment was tailored to have a large response when running the rotor close to its bending critical speed. First, damping the system by using a simple velocity-feedback controller was studied. The parameters of the controller were defined experimentally from the measured data. According to the simulations and the experiments performed, the velocity-feedback control system reduced vibration levels significantly. The controller made it possible to run the rotor over the critical speed. Second, a feedforward system, based on an adaptive finite-impulse-response filter, was designed to compensate disturbances due to mass imbalance. The coefficients of the filter were adapted by a least-mean-squares algorithm. The response due to mass imbalance in the rotor was significantly decreased. The simulations and experiments showed that the adaptive filter could be used as a supplementary system to the feedback system.